Base 10 Subtraction and SeeSaw

Students will:

• Be able to use the Number Pieces App to show their understanding of subtracting numbers less than 100 and post their understanding to SeeSaw.

Vocabulary Words:

1. Base 10 Blocks: Base 10 Blocks are rods and single blocks that break down numbers into 10’s and 1’s.

To prepare for this lesson:

Before the lesson, teachers must set up SeeSaw accounts for their classes and invite parents to join.

Note: SeeSaw has many other tutorials on their website and Help Center.

• Please view the TEACHER video on using SeeSaw in the classroom.
   
• Students should also know the basic features of SeeSaw. 
   
• Please view the following videos to decide how your students will access SeeSaw.  Students can access it with email, a class code, or a QR code. 

  • Get Students Started on Seesaw: Sign in with a code

  •  Student sign-in using email

  • Here is a student video on how to use SeeSaw. 

  • The SeeSaw app needs to be downloaded on student devices or bookmarked on computers. 

• For this task, students need the Number Pieces app. It is available on all devices as an iOS app or website. 

  • Watch the video tutorial on the Number Pieces app.

  • Watch the Subtraction Video. 

See the Accommodations Page and Charts on the 21things4students website in the Teacher Resources. 

Directions for this activity:

1. The teacher reviews how to make numbers with base 10 blocks both with manipulatives and on the app.

2. After reviewing making numbers, the teacher shows a simple subtraction problem without borrowing.
   

3. Next, the teacher has students complete three-four problems, showing their understanding for subtracting with base 10 blocks.

4. The teacher then gives students each a different problem. The students use the app to solve the problem and then take a screenshot of their work to post to SeeSaw.

5. Students open the SeeSaw app and press the “+” sign, then select the camera roll icon to select their screenshot.

6. Next, students select the draw tool to label their picture.

7. After labeling their picture, students tap the microphone and explain their thinking.

8. When finished, students select the green check to add it to their journal.

Note: Here is a photo of the steps to add and explain a photo in SeeSaw:

Different options for assessing the students:

• Observations
• Check for understanding
• Teachers can see what students have posted to their journal from the Teacher side of SeeSaw. They are able to leave feedback for students and intervene with any students who do not get the subtraction concept.